A brilliant idea for a horror movie set in a nursing home.

“The Rule of Jenny Pen” likes to follow in a tradition of different kinds of horror films, ones that involve elderly people and puppets. So why not combine both elements into one movie?

Whether were talking about aging child stars like in “Whatever Happened to Baby Jane” or crazy old people like in “The Visit” or “The Front Room,” elderly people can be scary in horror movies, based on how they behave and how younger others deal with them. And I remember my friend telling me they scare him in this genre. Now before you accuse me of anything, I don’t write the screenplays for those films, and if you are insulted, then you’ll have to complain to those writers.

Toys and puppets are going to be found every now and then in the genre, as demonstrated with Chucky in “Child’s Play” or Billy in “Saw” or the doll in “Longlegs” or more recently the cymbal-banging monkey in “The Monkey.” And in “The Rule of Jenny,” there are moments when you can hint that the main toy puppet is a gift from the Devil himself, based on how the screen lights up red.

We begin with Geoffrey Rush as Judge Stefan Mortensen ruling out a sentence before succumbing to a stroke, which has him placed in a nursing home. We see him confined to a wheelchair but still able to talk, but is helpless to save an old smoker from burning himself.

And we also see John Lithgow using a British accent as another patient named Dave Crealy, who has a puppet named Jenny Pen on his hand, and this is one of those horror movie characters the camera closely zooms in on. Stefan begins to get tormented by him, like when Dave pours urine on his body, and the nurses think he’s having a nightmare.

So, I think we can agree “The Rule of Jenny Pen” is going to get stranger and more twisted as their stay continues. Consider how Dave tests Stefan’s patience by not only telling him that his condition will get worse, but also kicking and making him tear up. This is almost like a twisted version of Steve Martin’s legs getting whipped by Michael Caine in “Dirty Rotten Scoundrels.

Stefan is not the only victim, as Dave makes another patient named Tony lick Jenny’s butt, and pulls on his catheter like it’s a painful game of Tug of War. And he likes to make Eunice (Hilary Norris) believe her family is waiting for her outside the facility. Think of it like a family making their senile grandma go to the bathroom on her own, and getting lost in a movie theater with multiple showings of a major blockbuster, except it’s much darker.

Of course the staff wouldn’t believe Stefan when he stands up against Dave, for obvious reasons that would include his age and condition. Even before this movie existed, I’ve seen this kind of thing before. But because it’s an IFC Films-distributed horror film, there’s less irritating dialogue of that notion, which is a good thing to me.

“The Rule of Jenny Pen” allows Rush and Lithgow to give entertainingly twisted performances and its ideas keep us going. There are scenes when the two Grumpy Old Men (I had to say it) spit at each other, which feels tedious, and there isn’t much basis for the bad things Dave engages in with the doll. But at the very least, it’s nowhere near as disgusting or stressful as “The Front Room,” which didn’t even know who its targeted audience was. This one is made for people who appreciate the elevated horror genre, and who would love to see Rush and Lithgow stepping outside their comfort zones. The screenplay by Eli Kent and James Ashcroft (the director) may retire early, but they sure know kind of horror film they want to represent.

In Select Theaters Tomorrow